It has long been desirable to have a removable auxiliary lens assembly attached to eyeglasses. Professional baseball players have used “flip-up” auxiliary lenses for more than four decades to protect their eyes from the sun, but to allow them unrestricted vision in the event the ball was hit in their vicinity.
U.S. Pat. No. 3,252,747 to Robins (“Robins”) discloses an eyewear system specifically designed for persons who are farsighted. The device includes an assembly in which an auxiliary frame assembly containing lenses may be rotated about the horizontal axis and remain attached to a primary assembly so as to locate the lenses the proper distance to the eyes every time the device is lowered into place. A significant disadvantage of this design is that it is unattractive, overly complicated, impossible to segregate from the primary frame, and does not permit or accommodate anyone other than farsighted individuals.
U.S. Pat. No. 6,089,708 to Ku (“Ku”) discloses a connecting member having spaced connecting plates for attachment to the bridge portion of a primary lens assembly. The connecting plates have magnetic members that act cooperatively with a complimentary magnetic member inserted in a hole on the bridge. The front of the connecting part has an open communication to a polygonal shaped holding room. The auxiliary frame has connecting rods extending above the bridge portion, and supporting an intermediate portion having a polygonal shape, receivable and rotatable in the holding room. A significant disadvantage of this design is that it is unattractive, overly complicated, and resists easy and immediate removal of the auxiliary lens assembly.
U.S. Pat. No. 3,238,005 to Petitto (“Petitto”) discloses the combination of a primary lens assembly and auxiliary lens assembly. The auxiliary assembly has flexible sidewall projections with openings that can be assembled onto lugs (pins) extending perpendicularly from the sides of the primary assembly, allowing the auxiliary assembly to be pivoted upwards, and back downwards. Leaf springs mounted on the auxiliary assembly engage surfaces of the primary assembly to urge the auxiliary assembly into position. A significant disadvantage of this design is that it is unattractive, overly complicated, and resists easy and immediate removal of the auxiliary lens assembly.
As stated, these and other mechanically clipped on devices for holding auxiliary lenses are cumbersome and unattractive. More recently, numerous attempts have been made to magnetically attach an auxiliary lens assembly to a primary lens assembly.
U.S. Pat. No. 4,070,103 to Meeker (“Meeker”), in one embodiment discloses a primary lens assembly having a slidably attachable auxiliary lens assembly. In this device, the primary lens assembly is made of magnetizable material and auxiliary lenses are individually securable to the primary lens assembly by a magnetic band inserted in a groove on the inside surface of the individual auxiliary lens assembly. This design is not pivotal, and the auxiliary assembly must be physically removed.
U.S. Pat. No. 5,416,537 to Sadler (“Sadler”) discloses a primary lens assembly having a first magnetic member attached vertically to the front surface of the primary lens assembly, and a second magnetic member attached in a corresponding position on the back surface on an auxiliary lens assembly. The magnetic members are arranged for engagement to secure the auxiliary lens assembly to the primary lens assembly. This design is not pivotal, and the auxiliary assembly must be physically removed.
U.S. Pat. No. 5,568,207 to Chao (“Chao”), in one embodiment, also discloses a magnetically adhered auxiliary lens assembly, with the additional feature of arms extending from the side portions of the auxiliary lens assembly, over magnet retaining projections and extensions of the primary lens assembly. The arms engage with, and are supported on, the primary lens assembly extensions to prevent disengagement of the auxiliary lens assembly upon downward movement of the auxiliary lens assembly relative to the primary lens assembly. This design is not pivotal, and the auxiliary lens assembly must be physically removed.
Many of the recent developments in auxiliary eyewear systems such as those described above rely on a combination of mechanical and magnetic engagement. The magnetic engagements themselves are insufficiently strong to retain the auxiliary frame assembly. Additionally, the auxiliary frame assembly must be removed from the primary frame assembly, and then handled and stored separately when it is necessary for the eyeglass wearer to look only through the lenses of the primary frame assembly. They do not enjoy the advantages of the early flip-up designs, which permitted quick movement of the auxiliary assembly out of alignment with the primary assembly without separating them from the primary assembly.
U.S. Pat. No. 6,474,811 to Liu (“Liu”) discloses a magnetically attached auxiliary lens assembly in which the auxiliary assembly can be magnetically attached to either the inside or outside of extensions having magnets on the primary assembly. The auxiliary assembly is pivotal upwards, removing the pivotal alignment of the auxiliary and primary lenses. A significant disadvantage of this design is that it is unstable, relying on tenuous repositioning and magnetic forces alone to align and support the auxiliary assembly to the primary assembly. Another significant disadvantage of this design is that it causes the auxiliary frame to be positioned into the forehead of the wearer, making raising the auxiliary assembly fully perpendicular to the primary assembly impractical.
U.S. Pat. No. 6,301,953 to Xiao (“Xiao”) discloses an auxiliary lens assembly having pivots mounted above the lenses and attached by long, L-shaped shelter arms. The shelter arms are attached to supporting arms having magnet holding housings attached at their ends. Magnets are inset in the housings for engagement over rearwardly protruding rim lockers. One disadvantage of this design is that it fails to limit the rotation of the auxiliary lens assembly. Another disadvantage is that it is aesthetically unappealing, due in part to the long shelter arm requirement. Another disadvantage is that it relies on a bridge magnet or bride hook for stability. Another disadvantage is that the device relies on magnetic force to pull the magnetic housing forward, over a rearward protruding lens locker, requiring the user to push the auxiliary frame awkwardly rearward, into the primary frame, to disengage the magnetic housing from over the lens locker. Another disadvantage is that the device is complex and expensive to manufacture.
Each of these designs requires a lens that is limited in width to accommodate the magnets and mechanical engaging apparatus on the outside of the lenses. As a result, peripheral vision through the lens is limited. This can give rise to both convenience and safety issues. For example, a nearsighted person trying to change lanes on a freeway Is forced to rotate this or her head significantly further around to allow alignment of their eyes through the lens in the direction of the vehicle blind-spot. These processes increase the time required to effect the maneuver, and results in the increased time in which the direction in which the car is traveling at high speed is not visible. Problems occur again when trying to back up a vehicle.
The prior art magnets and mechanical engaging apparatus on the outside of the lenses used to attach the auxiliary lens assembly to the primary lens assembly typically involve extensions on the primary frames. The extensions must be large enough to accommodate magnets that are large enough to exert the necessary force to retain the auxiliary lenses in place. Similarly, the prior art auxiliary lens assembly will require extensions that, in one manner or another, protrude over the extensions of the primary frame assembly and include retainers for supporting auxiliary magnets.
The resulting disadvantage is that the prior art design for primary and auxiliary lens assemblies involve delicate soldering of numerous extraneous parts which extend from the sides of the lens assemblies. The only purpose of the several extraneous parts is to support the magnets and/or mechanical engagement of the auxiliary frame assembly to the primary frame assembly.
U.S. Pat. No. 4,070,103 to Meeker discloses, eyeglasses having attachable pairs of lens rim covers. The lens rims are made of magnetizable material. A magnetic strip is provided in a groove on the inside surface of the lens cover. When the lens rim cover is placed on the rim, it is magnetically supported. A disadvantage of this invention is that the magnetic band made of conventional magnet materials is bulky and heavy, and the entire assembly is overly complicated. Also, band-like magnetic materials must be ductile enough to prevent breakage, and thus the compositions of the magnetic materials suitable for use is limited.
U.S. Pat. No. 5,786,880 to Chao discloses a spectacle, or eyeglass, frame including a primary frame and a secondary frame having one or more magnetizable members embedded within the eyeglass frame prior to magnetizing the members. The magnetizable members are then electroplated, painted, and magnetized with a magnetizing machine, such as an electromagnetic machine. A disadvantage of this design is that the resulting eyeglass frame is relatively bulky and the discrete magnets made of conventional materials lack sufficient power and life to support the auxiliary lens assembly to the primary lens assembly.
U.S. Pat. No. 6,412,942 to McKenna and Smith (“McKenna”) discloses one embodiment where a heat-treated magnetic alloy auxiliary frame assembly configured to magnetically couple the auxiliary lens assembly to the primary lens assembly is employed. Heat treating of a spinodal decomposition alloy magnetizes the alloy and, therefore, the auxiliary frame is formed entirely from a magnetic alloy. The disadvantage of this design is in the manufacture cost and challenges associated with heat treating a thin metal frame, as well as the lack of strength and life of the magnetic field.
McKenna, in another embodiment, discloses an auxiliary frame that is at least formed from a magnetic alloy, wherein the alloy is uniformly distributed throughout the auxiliary frame. Specifically, McKenna emphasizes uniformity of magnetic material throughout the auxiliary lens as an advantage over the use of discrete components. However, there are disadvantages associated with employing uniformly distributed magnetic materials throughout the auxiliary lens assembly. In particular, the cost of metallurgy associated with the manufacture of uniformly distributing magnetic materials can be high.
U.S. Pat. No. 6,331,057 to Strube (“Strube”) discloses a clip-on option for the auxiliary lens assembly in which the auxiliary lens assembly is held by small but powerful cylindrical magnets made of zinc-coated neodymium, located in the auxiliary bridge region and the primary bridge region. The magnetic material is disclosed as preferred for its superior remanence and coercivity.
It can thus be seen that there is a need to develop a design for a combined lens assembly which is attachable without the numerous extraneous parts and soldered assemblies of traditional designs, which encumber their appearance and limit the lens width. There is also a need to provide such a device that permits insertion of wider lenses to improve peripheral vision. There is also a need to provide a system capable of magnetic support in which the magnetic force is sufficient to support attachment of the auxiliary lens assembly to the primary lens assembly without the requirement of coextensively aligned mechanical engagement. There is also a need to simplify the structure and assembly of primary lens assemblies. There is also a need to provide a magnetically attached auxiliary lens assembly that is light-weight. There is also a need to provide an auxiliary lens assembly that is easily attachable to the primary frame assembly, without the need to maneuver extraneous component assemblies into engagement.